I've been using this program tons recently, it's really been super helpful. Thanks for making it!
There are some features I still would love to see though. Is there a way to place multiple tiles at once? Like, say I select a 3x3 tree; I want to place the entire tree with one click, rather than going back and forth between the tileset to place each block of the tree.
Similarly, a feature that'd let you make meta-tiles that would auto-tile would be nice, sort of like what the RPG Maker programs let you do with textures like grass, water, sand, etc. For example, if I were placing grass tiles on dirt, instead of manually placing the border between the grass and dirt in each instance, I'd put the transition-grass tiles in a template and then just draw a blob of grass and let the program automatically place the transitions in the appropriate positions.